Telephone-switch



2 Sheets-Sheet 1.

(No Model.)

C.' N. SANDBECK.

TELEPHONE SWITCH. I

Patented Nov. 3, 1896 I I I I I I l l I II iiiiL WITNESSES ATTORNEYS.

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UNITED STATES PATENT OFFICE.

CHRISTIAN N. SANDBECK, OF HARMONY, MINNESOTA. I

TELEPHONE-SWITCH.

SPECIFICATION forming part of Letters Patent No. 570,773, dated November 3, 1896.

A lication filed A il 8,1896. Serial No- 586,651. (No model.)

T0 at whom it may concern:

Be it known that I, CHRISTIAN N. SANDBEcK, of Harmony, in the county of Fillmore and State of Minnesota, have invented a new and useful Improvement in Telephone-Switches, of which the following is a full, clear, and exact description. 7

This invention relates to switches for telephones, and the object is to provide a simple means by which two telephones in a series may be placed in connection without preventing other telephones in the series or on the same line from being put in communication, and, further, to so construct the switch that conversation carried on between two telephones cannot be heard through other telephones that may be in the same circuit.

I will describe a switch embodying my in-- vention and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a diagrammatic view of a switch mechanism embodying my invention. Fig. 2 is a view in elevation of the switch mechanism, and Fig. 3 is a section through the line 3 3 of Fig. 2.

The switch comprises a casing 1, within which is placed a lever 2, pivoted at one end to one side wall of the casing and having its other end extended outward through the opposite side wall and terminating in a hook, with which the receiver may be engaged to hold the lever in its lowermost position. To raise the lever when the receiver is removed, I employ a spring 3, secured at one end to the lever and at the other end to the casing. Extended transversely across the interior of the casing is an upper contact-spring 4 and a lower contact-spring 5. These contactsprings are employed for closing circuits leading in different directions, as will be more fully explained.

Resilient fingers 6 7 are extended downward from the upper end of the casing and have their free ends turned rearward to be engaged with the contact-spring 1. These fingers 6 and 7 are respectively moved into engagement with the contact-spring 4 by means of spring-plates 8 9, secured at their upper ends to the door of the casing and hav-' ing their lower portions adapted to engage withthe lower contact-spring 5. At the point designed to engage with the spring-fingers the plates 8 9 are provided with insulating. material 10. From the lower portion of the plate 8 a hook-arm 11 extends inward and is adapted to engage its hook end with the lever 2, and from a plate 9 a similar hook-arm 12 extends inward and is adapted to be engaged with the said lever. A push-pin 13 extends outward from the plate 8 through an opening in the door of the casing, and a similar pushpin 14 extends outward from the plate 9.

Each push-pin is here shown as provided at its outer end with a thumb-piece or button,

and it will be seen that the inner ends of the push-pins have loose engagement with their respective plates.

A circuit-closer is secured in the lower portion of the casing. As here shown, this circuit-closer comprises two spring-fingers 15 16, having overlapping ends adapted to be engaged by the pressure of the lever 2 when said lever is in its lowermost position. Above the lever and adapted to be engaged thereby when in its upper position is a contact-spring 17.

I have not deemed it necessary to show in Figs. 2 and 3 all of the electric connections, such as the transmitter, the receiver, the induction-coil, the generator, and the wiring, as such parts are more conveniently shown in Fig. 1, which I will now describe.

On the upper side of the casing are mounted binding-posts E and W, which I will term east and west binding-posts, as they are to receive line-wires leading in different directions. Posts G G are also mounted on the casing, and these, for the purpose of this description, I will term grounding-postsflas they are engaged by grounding-wires.

From the binding-post W a Wire 18 leads to the spring-finger 7, and this posthas also a connection 19 with one pole of a magneto-generator G and a connection with the plate 8 through a wire 21. From the other pole of the magneto-generator a wire 22 extends through the circuit-closer 15 16 to one pole of the bellmagnet 23, and from the other pole of the bellmagnet a wire 24 extends to a connection with the spring-finger 6. This spring-finger 6 is in connection with the binding-post E and the plate 9,. respectively, by means of the wires 25 26.

Located in the casing 1 is an induction-coi I, having one end of its primary coil in connection, through the Wire 25, with the lever 2, and the other end is connected to the contact 17 by a wire 26, which, as here shown, contains a transmitter T and a battery B. Oneend of the secondary coil of the induction-coil is connected by a wire 27 with the binding-post G, and the other end of said coil is connected by a wire 28 with the contactspring 5, and, as here shown, this wire 28 is in connection with the receiver R.

The operation may be described as follows:

It will be understood that the instrument is designed for use where several are connected in series. is with the lever 2' in its lowermost position and closing the oircuit-closer 1516, so that when a callis made the current will pass through the bell-magnets and cause the bell to be sounded.

Assuming that A on the west side desires to conversewith C on the east side, A will make the usual call to the central oftice, where the connection will be made between the two telephones. After receiving theansWer-call A will ring his call to let G know that the call is from the west. Then C will push the plate 8 of his instrument inward to engage the hook 11 with the lever 2, and at the same time A will push the plate 9 of his instrument inward to engage its hook with the lever 2. Now a conversation maybe carried onbetween 1' and C and the other telephones on the lineeast of (1 may also be operated without interfering with A and C, but the conversation of A and 0 cannot be heard through the other telephones-0t the series. The line west of A can be operated in the same way. If B at another telephone interferes by pushing in a plate Sor 9, it would simply stop the conversation between A and G, as the line would be grounded at B from botheast and west. It will be seen from the diagram of the circuit that it isimpossible for The normal position of the parts B to hear a conversation between A and C "unless B disconnects his receiver from his telephone and connects it directly withthe line on top of the instrument.

Having thus described my invention, I

. claim as new and desire to secure by Letters Patent 1. A telephone-switch, comprising a casing, two spring-contacts arranged therein,contactfingers adapted for engagement with one of the spring-contacts, plates movable to engage the other of said spring-contacts and to move the contact-fingersto close a circuit, and electrical connections, substantially as specified.

2. A telephone-switch, comprising a casing, a pivoted lever therein, adaptedto c'l'ose elec-- tric connections, contact-springs extended transversely in the box, contact -'fi'n-gers adapted for engagement with one ofsaid contact-springs, spring-plates inthe casing adapted for engagement with the other of said contact-springs, and to force the fingers into contact with their contact-spring, and

pins extended outward from said spring plates.

A telephone-switch, comprising a casing, alevcr pivoted therein, spring-finger having connection with a line-wire and with a bell-magnet, another spring-finger having connection with said bell-magnet, a con-tact? spring having: connection with a gronndwvire and adapted to be engaged by the springfin-gers, a spring-plate having connection with the bell-magnet and with the line-wire mentioned, and other spring-plates having connection with another line-wire and with the bell-magnet, a contact-spring with which said plates are adapted to engage, an inductioncoil, having connection with the last-named contact-spring, with the pivoted lever and with: a gl-ound-wire, and a-receiver and transmitter located in the-circuit, substantially as specified.

CHRISTIAN N. SANDBEUK.

Witnesses:

ToLLEF SANDERSON, ARNE' KIRKELIE. 

